A fuel pump includes a pump body in which a fuel passage is defined, and compresses and discharges fuel flowing in the fuel passage. In the fuel pump, pressure pulsation of fuel causes noise, and wearing or breakage in the piping components. JP 2013-60945A describes a pulsation damper which reduces pressure pulsation of fuel for a fuel pump.
Specifically, the pump body has a concave portion recessed from the outer surface, and the fuel flowing through the fuel passage flows into the concave portion. An opening of the concave portion is covered with a cover to tightly seal, such that a housing chamber is formed inside. A diaphragm is arranged in the housing chamber, and is elastically deformed by receiving the pressure of fuel so as to reduce the pressure pulsation of fuel.